SpaceX released some of the details about the helium leak in the Falcon 9 rocket that scrubbed Monday’s launch attempt of the SpaceX cargo resupply mission to the International Space Station. Here is what the company said: “During Monday’s launch attempt, preflight checks detected that a helium valve in the stage separation pneumatic system was not holding the right pressure. This meant that the stage separation pistons would be reliant on a backup check valve. No issue was detected with the backup valve and a flight would likely have been successful, but SpaceX policy is not to launch with any known anomalies. We have brought the vehicle back to horizontal and are replacing the faulty valve, as well as inspecting the whole system for anything that may have contributed to the valve not working as designed.”
SpaceX-3 is slated for liftoff Friday at 3:25 p.m. EDT. Saturday was chosen as the backup day for launch with a launch time of 3:02 p.m. EDT.
The International Space Station Program and SpaceX have selected Friday, April 18 for the next launch attempt for the Falcon 9 rocket to send the Dragon cargo craft on the company’s third commercial resupply mission to the space station. Launch is scheduled for 3:25 p.m. EDT. The NASA Launch Blog and NASA TV coverage will begin at 2:15 p.m.
A launch on Friday results in a rendezvous with the space station on Sunday, April 20 and a grapple at 7:14 a.m. NASA TV coverage will begin at 5:45 a.m. with berthing coverage beginning at 9:30 a.m.
SpaceX has settled on a backup launch date of Saturday, April 19 for the best pair of launch dates for the science payloads being delivered to the station. If needed, a Saturday launch would occur at 3:02 p.m. This would be a three-day transit to the station instead of two days with grapple on Tuesday, April 22.
If NASA and SpaceX officials decide to attempt to launch SpaceX-3 to the International Space Station on Friday, there is a 40 percent chance of favorable weather. The Air Force 45th Weather Squadron issued its L-3 forecast, which predicts a chance of showers and thunderstorms that could result in violating the Thick Cloud, Lightning and Flight Through Precipitation rules.
SpaceX’s launch to the International Space Station was scrubbed today due to a helium leak on the Falcon 9 first stage. The next launch opportunity would be Friday, April 18 at 3:25 p.m. EDT if the issue can be resolved.
SpaceX released this photo today of its Falcon 9 rocket and Dragon spacecraft standing on the pad at Launch Complex 40 at Cape Canaveral Air Force Station in Florida. The Dragon is loaded with about 5,000 pounds of equipment, science experiments and supplies bound for the International Space Station and its crew of six astronauts.
Good morning from Kennedy Space Center in Florida! The sun has risen on launch day for the SpaceX-3 mission which remains on schedule for liftoff at 4:58 p.m. EDT from Cape Canaveral Air Force Station adjacent to Kennedy. The weather forecast calls for an 80 percent chance of acceptable conditions this afternoon at launch time. Meteorologists will be on the lookout for thick clouds that could develop as the day progresses. The Falcon 9 rocket and Dragon spacecraft were lifted into launch position yesterday, as seen in this picture from NASA TV. We’ll begin our continuous countdown coverage on the NASA Launch Blog at 3:45 p.m. NASA TV coverage begins at the same time here.
International Space Station Program officials, the international partners and representatives of SpaceX agreed Sunday to proceed with Monday’s scheduled launch of the SpaceX Falcon 9 rocket and its Dragon cargo craft on the company’s third commercial resupply mission to the orbital laboratory.
After a series of meetings and reviews of procedures, flight controllers, engineers and managers concluded that the SpaceX-3 mission could be conducted as planned without violating any launch commit criteria despite the loss Friday of a backup computer command relay box called a multiplexer/demultiplexer (MDM) that resides in the station’s S0 truss. The problem with the box, which measures 10.5 x 14.9 x 16.4 inches and weighs 50.8 pounds, occurred during a routine health check of the device. The prime multiplexer continues to operate normally. This pair of MDMs provide commanding to the station’s external cooling system, Solar Alpha Rotary joints, Mobile Transporter rail car and insight into other truss systems.
The engineering teams reported to mission managers that the station possesses enough redundancy to allow the SpaceX mission to launch Monday at 4:58 p.m. EDT from Launch Complex 40 at the Cape Canaveral Air Force Station, Fla. In advance of launch, the station’s Mobile Transporter will be moved to the proper position on the truss later today and after Dragon’s launch, the station’s solar arrays will be oriented Monday to the correct angles for the scheduled capture of the U.S. cargo craft on Wednesday and its berthing to the Earth-facing port on the Harmony module. These are steps that would properly configure the station for the mission even if the prime MDM experiences a problem.
Additionally, preparations are underway for a contingency spacewalk by two of the Expedition 39 crewmembers no earlier than around April 22 to replace the failed MDM with a spare housed inside the station. Mission managers approved a plan for the preparation of two of the U.S. spacesuits on the station and the replacement of a fan pump separator on one of the suits prior to the spacewalk. That work will begin immediately. The move of the Mobile Transporter rail car to another worksite from its current location will clear the area on the S0 truss for the spacewalking astronauts to gain access to the failed MDM during the planned excursion. The station crew will also be readying the spare MDM for its staging in the Quest airlock prior to the spacewalk.
International Space Station Program officials and representatives of SpaceX decided Saturday to continue preparations for the launch of the Falcon 9 rocket and the Dragon cargo craft to the space station Monday from Launch Complex 40 at the Cape Canaveral Air Force Station, Fla., despite the failure Friday of a backup computer component that provides redundancy for commanding the Mobile Transporter rail car on the truss of the station. A final decision on whether to launch Dragon Monday will not be made until another status meeting is conducted Sunday morning.
NASA has rescheduled its SpaceX prelaunch briefing allow for operational reviews in the morning. It now will be held at 1 p.m. EDT at the agency’s Kennedy Space Center in Florida. Also, the SpaceX-3 Science and Technology Cargo briefing will take at 2 p.m. For updates on the schedule of events for Sunday, call the Kennedy News Center recording at 321-867-2525.
The component, called a multiplexer demultiplexer (MDM) is one of more than a dozen housed on the truss of the station that routes computer commands to various systems on the outpost. The failure Friday to a box called EXT-2, a backup box to a prime component in the S0 truss that measures 10.5 x 14.9 x 16.4 inches and weighs 50.8 pounds, occurred during a routine health check of the device. The prime multiplexer continues to operate flawlessly, and there has been no impact to station operations. The crew was informed of the problem and is in no danger, continuing its normal complement of research work and routine maintenance. A reboost of the station using the ISS Progress 53 thrusters was conducted Saturday as planned and placed the laboratory at the correct altitude for Soyuz crew landing and launch operations in May.
Station program officials, flight controllers and teams of engineers are working to determine whether there is any risk to launching the SpaceX cargo craft Monday. They will evaluate whether the station has enough redundancy to permit the launch to proceed, which would result in Dragon arriving at the station Wednesday where it will be grappled and berthed to the Earth-facing port of the Harmony module by Expedition Commander Koichi Wakata of the Japan Aerospace Exploration Agency and NASA Flight Engineer Rick Mastracchio. The station’s Canadarm2 robotic arm that would be used to capture and berth Dragon has other redundancy capabilities not affected by the backup MDM failure.
While a final decision on the SpaceX launch is being reviewed, another team of engineers is laying out a timeline for a contingency spacewalk that is required to replace the failed spare MDM. No date for the spacewalk has been scheduled. Such a spacewalk is one of the so-called “Big 12” spacewalks that station crews train to execute for the loss of a critical component on the complex.
For now, Dragon remains scheduled for launch Monday at 4:58 p.m. EDT.
Air Force weather forecasters said there is a 70 percent chance of acceptable conditions Monday afternoon for the 4:58 p.m. EDT launch of the SpaceX-3 mission. The concern is that thick clouds will develop during the afternoon as the countdown winds toward liftoff. If the launch is scrubbed Monday, the next opportunity will come Friday, April 18. Conditions that day are expected to be worse than Monday’s, with the forecast calling for a 40 percent chance of acceptable weather.